When running configure like this:
sh -c 'CONFIG_SITE=./config.site ./configure'
the site script is loaded ...
loading site script ./config.site
but not propagated to the popt directory
configuring in popt
running /bin/sh ./configure --cache-file=.././config.cache
--srcdir=.
loading cache .././config.cache
This is not very good as it makes it impossible to use the
site script to e.g. turn optimisation off by writing
CFLAGS='-g' in the file. If you try, optimization will be
off everywhere except in the popt code ;-((